I am making a site directed mutation in a gene using PCR. The two PCR pieces are then purified using a kit. PCR shows that each piece is the correct size (200bp and 1100bp) and a single band. After running the assembly PCR step, I end up with a smear on my gel. I have changed temperatures and concentrations of the primers and PCR pieces.
Any suggestions on things to check/change?
Thanks in advance,
Derek